Automatic slip joints



Dec. 22, E959 L. LE BUS, SR

AUTOMATIC SLIP JOINTS 2 Sheets-Sheet 1 Filed July 9, 1956 INVENTOR. FL [2 54/5 5/:

ATTOPA/[y Em. 22,, 395% F. L. LE BUS, SR

AUTOMATIC SLIP JOINTS 2 Sheets-Sheet 2 Filed July 9, 1956 INVENTOR. FL ZeBus 5/: BY ATTORNEY Q w I u United States Patent AUTOMATIC SLIP JOINTS Franklin L. Le Bus, Sr., Longview, Tex.

Application July 9, 1956, Serial No. 596,776

2 Claims. (Cl. 255--23) This invention relates to rotary drilling equipment and more, particularly, but not by way of limitation, to a slip joint structure for a rotary drilling string utilized in the drilling or coring of oil and gas well bores, and for any other useful operation in a well bore where it is desired to raise the top part of the drill pipe string without disturbing a lower section of the drill pipe string so that any drill bit, coring bit, fishing tool, or sand testing tool will not be moved, or its position in the well bore will not be altered by raising the upper part of the drill pipe stem. This application is a continuation-in-part of my co -pending application Serial No. 579,491, filed April 20, 1956, and entitled Automatic Slip Joint.

In the rotary drilling of oil wells, particularly deep bores, the, drill bit is secured on the lower end of a drilling string which is rotated at the surface of the well through the drilling rig which includes a rotary table and cooperating kelly therewith. The kelly. is usually. a square shaped elongated member disposed in an aperture in the rotary table for movement downwardly therethrough. As the drill string, proceeds downwardly, it is necessary to periodically add extra joints of drill pipe for making additional depth into the well bore. When this is necessary, the kelly is usually moved upwardly above the apertured rotary table, and the additional joint of pipe is inserted between the kelly and a previous top section of the drill pipe whereupon, the drilling string is again lowered to begin the drilling operation. In the present available equipment for inserting an additional joint of pipe, it is usually necessary to raise the drill bit, or core bit from the bottom of the well an equal distance that the drill string is raised so that the extra section or joint of pipe may be added to the string.

As greater oil reserves are being sought, wells are being drilled to increasingly greater depths with resulting greater hazards and expenses. For this reason a driller desires the greatest amount of information available relating to the sub-surface formations encountered in a well bore. The usual method of obtaining the desired data is the well known procedure of coring the formation. The core barrel, which is normally used to drill through the formation, drills over a small diameter section of the formation and retains a solid unit thereof. within the core barrel. This solid unit or core sample is mechanically recovered and brought to the surface of the well for careful analysis. The drilling of a Well to a depth of ten thousand feet or over with a core barrel on the bottom of the drill pipe is a costly project, and for this reason it is desired to obtain maximum results with the core barrel. As a result, the use of diamond studded core bits has become generally accepted in the industry. These diamond bits are quite expensive, and every effort is made to prolong their useful life.

Most wells are drilled with a well known drilling tool called a rock bit which rotates on the bottom of the bore hole. These rock bits are provided with hardened teeth to grind up, the formation, and during the drilling of hard 2,918,259 Patented Dec. 22, 1959 formations, such as granite and chert, many of the hard teeth are often broken off and will float in the circulating mud around the drill pipe with the small pellets of broken formation. In this condition the pellets do not do any particular damage or interfere with the drilling or coring operation of the rig. When the bit is raised old? the bottom of the well as heretofore mentioned, however, these vfloating hazards settle down into the borehole, and when the bit is lowered to continuethe drilling or coring operation, the pellets and bits of hard teeth are trapped under the cutting surface of the bit. When rotation. of the bit is continued, the broken off hardened portions under the drill or core bit will start a rolling action that causes considerable damage to the bit, particularly the expensive diamond core bit, so. that in a veryshort time it becomes practically useless.

This invention is generally concerned. with an improved slip joint provided with cooperating control spline members having helical tapered surfaces which greatly facilitate the telescopic operation of the slip joint when it is necessary to add additional sections of pipe to the drill string for a continued drilling operation. The spline members provide for the insertion of the additional sections of drill pipe without lifting of the drilling bit or core bit off the bottom of the well bore. It is also well known in rotary drilling that telescopic sections have been used in the.

braking power was not applied would have a tendency to.

cause crooked hole drilling. This invention also provides a tool which permits substantially any predetermined weight or variation in Weight that may be desired by the driller to, enable the bit head to penetrate the formation being drilled at a smooth, efficient speed of penetration; This is, particularly desirable when drilling in deep bores with long and heavy strings of drill pipe. The driller will usually vary the weight of the drill string acting upon: the drill bit by utilization ofjthe braking apparatus atthe-surface of the well, but this practice is subject to the normal inaccuracy of the human element. With predetermined: knowledge of the weight of the core barrel, the desired number of ,dri ll collars and a partial. section of, the slip joint the necessary weight for an eflicient andregulated penetration may be readily calculated and maintained.

Furthermore, the present invention utilizes tlte male portions of the control spline members for driving thev entire drilling tool when the slip, joint is in an extendedposition. This design and construction also precludes an accidental, disconnection of the complete slip joint without the necessity of providing separate clutch members on the tool. In addition, the novel slip joint permits utilization of packing members at the top of the tool only to preclude flow of drilling fluid between the inner and outer housing thereof during the drilling operation.

It is an important object of this invention to provide an improved. slip joint for drilling strings which provides for the addition of extra sections of pipe in the drilling string without lifting the drilling bit from the bottom an improved slip joint which will p'ermit insertion of an additional joint of drill pipe without removal of the drill bit from the bottom of the well bore and yet permit operation of the drill bit when the slip joint is in an expanded open position.

And still another object of this invention is to provide an improved slip joint cooperating with a drilling string in such a manner as to permit any variation in weight as required in any drilling operation to penetrate formations being drilled in an efiicient manner.

And still another object of this invention is to provide an improved slip joint which controls the circulation of drilling fluid therethrough to the bottom of the drill bit in a manner to facilitate the drilling of the well bore, and yet preclude undesirable passage of the fluid through certain portions of the slip joint during utilization thereof.

And still another object of this invention is to provide an improved slip joint so designed and constructed to facilitate the telescopic operation thereof to an extended position and such that no additional rotation of the drill string is required in order to move the slip joint from an extended position to a contracted position.

And still another object of this invention is to provide a slip and safety joint for drill strings which is simple, practical and economical in its operation.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a broken vertical elevational view having portions in section depicting the upper portion of the novel slip joint.

Figure l-A is a view similar to Fig. 1 of the lower portion of the novel slip joint for interposition in a drill string and in an operating position.

Figure 2 is a broken elevational view of the lower portion of the novel slip joint in a position for beng extended, and with certain portions shown in dotted lines for purposes of illustration.

Figure 3 is a broken vertical elevational view of the upper portion of the novel sl'p joint in an extended position, and with certain portions shown in dotted lines for clarity.

Figure 3-A is a view similar to Fig. 3 of the lower portion of the novel slip joint in an extended position and having certain portions shown in dotted lines for illustration.

Figure 4 is a broken vertical elevational view partly in section of a porton of the novel slip joint in a fully extended position for drilling or backing oif. Referring to the drawings in detail, reference character 6 generally indicates a slip joint adapted to be interposed in a drill string (not shown) d'sposed in a well bore (not shown). A rotary kelly (not shown) cooperates with a rotary table (not shown) normally utilized for holding the drilling string at the surface of the well. The rotary table connects with the top string of the drill pipe (not shown) which extends into the well bore for connection at 8 with an upper sub or bushing member 10. The sub member 10 is connected through complementary threads 12 to a ylindrical housing 14 in turn threadedly secured at 16 to an outer drive body or sleeve 18 A plurality of circumferentially spaced male spline members or lugs 20 are provided on the inner periphery of the drive sleeve 18 in the proximity of the open end 22 thereof for a purpose as will be hereinatfer set forth; 4 An apertured packing stem member 24 is disposed within the upper sub member 10 and is slidably secured therein by the friction between the inner periphery of the sub member and a plurality of longitudinally spaced packing ring members 26 provided on the outer periphery of the stem member 24. The packing stem 24 is further provided with a plurality of circumferentially spaced clutch and stop members 28 spaced below the packing ring member 26. The clutch members 28 are of a substantially T-shaped configuration to provide a longitudinal downwardly extending lug 30 (Figs. 1 and 4) and a circumferential lug or stop member 32.

The stem member 24 is threadedly secured at 34 to an inner drive sleeve 36 which extends longitudnally substantially through the housing 14 and drive body 18. The sleeve 36 is provided with an outwardly extending tapered shoulder portion 38 disposed below the open end 22 of the drive body 13. A plurality of circumferentially spaced grooves or channels 40 of a substantially inverted J- shaped configuration to each other are provided on the outer periphery of the sleeve 36 adjacent the tapered shoulder 38. The grooves 40 are adapted to cooperate with the male spline members 20 for slidably securing the outer sleeve 18 over the inner drive sleeve 36 as will be hereinafter set forth. Each of the grooves 40 comprises a longitudinal groove or recessed portion 42 having the upper end 43 thereof open to receive one of the lug members 20. A substantially horizontal groove 44 is in communcation with the groove 42 and extends circumferentially on the sleeve 36 into communication with a second longitudinal groove 46 having the upper end thereof closed by a horizontal shoulder portion 48. The substantially horizontal groove 44 is provided with a partially helical surface or shoulder 50 extending between the grooves 42 and 46. A second tapered or partially helical shoulder 52 is provided on the sleeve 36 in communication with the open end 43 of the longitudinal groove 42. The lower surface of the lug members 20 is provided with a cooperating helical or tapered surface 54 to facilitate positioning of the lug members 20 within the J-shaped grooves 40.

The inside diameter of the cylindrical housing 14 is slightly larger than the inside diameter of the upper sub member 10 to provide for ease of operation of the slip jo nt during the telescopic movement of the outer drive sleeve 18 and housing member 14 with respect to the inner drive sleeve 36 and packing stem 24. The lowermost portion 56 of the inner drive sleeve 36 is provided with a threaded member 58 to secure the inner drive sleeve 36 and packing stem 24 to the drill string (not shown) disposed in the well bore therebelow.

Operation The upper bush ng member 10 is threadedly connected at 8 to the upper portion of the drill string (not shown) which extends downwardly into the well bore from the rotary table (not shown) at the surface of the well. Similarly, the inner drive sleeve 36 is threadedly secured at 58 to the lower portion of the drill string (not shown), thereby interposing the slip joint 6 within the drill string. The slip joint 6 is in an operating position when the male lug members 20 are disposed adjacent the upper shoulder 48 of the J-shaped grooves 40 as shown in Fig. 1-A. A right hand rotation of the upper drill string from the well surface is transmitted through the sub member 10 to the cylindrical sleeve 14 and the outer drive sleeve 18. The lug members 20 are disposed in the grooves 46 between the key members 60 and 62 (Fig. 2 and 3-A) which are formed on the inner drive sleeve portion 36 by the J-shaped grooves 40. Thus, the right hand rotation of the outer drive sleeve 18 moves the lug 20 into contact with the key 62, causing the inner drive sleeve 36 to rotate simultaneously with the outer drive sleeve 18. The rotation of the sleeve 36 is transmitted to the lower portion of the drill string through the threaded member 58. In this manner, the entire slip joint 6 and drill string will rotate for the drilling or coring operation.

A continuous downward feed of the kelly at the well surface (not shown) must be made as the drill bit 5. or core bit. (notshown) on f the lowermost end. of the drill string penetrates; the formation. The weight on the drill bit comprises the combined weight of the pack-. ing stem 24. and inner drive sleeve 36 and the structures. or housings seeured therebelow. Thus, the desirable weight can. be predetermined for the drilling operation. From the predetermined weight calculation, the speed of penetration is regulated to the speed of the drilling, and the operator will have to lower the kelly at approximately the same rate as the bit penetrates the formation to prevent the engagement between the lugs 20 and the shoulder 48 from reducing the weight on the hit. As soon as the kelly approaches the bottom of its feed, it is desired to add an additional joint of pipe to continue the drilling operation. It is desirable not to raise thecore bit during insertion of extra pipe sections so that detrimental pellets, rocks and the like cannot fall under the bit before lowering it back to the bottom of the well bore. The slip joint 6 is provided inthe drill string to permit raising of the kelly without moving the bit from the bottom of the well bore, and operates as follows.

When necessary to insert an additional section of drill pipe, the drilling string (not shown) is slacked off until the cooperating lugs 20 move downwardly in the groove 46 to a position (not shown) substantially adjacent the tapered shoulder 38. The drilling string is then rotated in a left hand direction and slowly raised upward within the well bore. The lug 20 will be moved into contact with, the, helical portion or shoulder 50 of the horizontal groove 44, and into the longitudinal groove 42 to a position as shown in Fig. 2. In this position, the outer drive sleeve 18 and cylnidrical housing 14 may be moved upward in. a telescopic arrangement with respect to the inner drive sleeve 36. and packing stem 24, asshown Figs 3-A, and 4. This movement is of sufi'icient length to permit additional drill pipe sectionsto be added to the. drill string at the surface of the well igthout moving the drill bit from the bottom of the well As hereinbefore set forth, the packing stem 24 is slidab1y; secured within the upper bushing 10 by the friction between the packing ring members 26 and the inner periphery of the bushing 10. The upwardmovement of the upper drill string will overcome the force of the friction to permit the bushing 10. to move upwardly with respect to thepacking stem 24, and position the packing ring members 26 within the cylindrical sleeve 14. The larger inner diameter of the sleeve 14 permits a free upward movement of the housing 14 and outer drive sleeve 18 until the lugmembers 20 are raised: into contact with the; clutch and stop members 28 as shown in Fig. 4. The lug members 20.will be positioned adjacent thecircumferential shoulder 32 and between the downwardly extending lug members 30. The shoulder 32 precludes an accidental complete disengagement of the outer drive sleeve 18 and inner drive sleeve 36. Furthermore, the drill string may be rotated when the slip joint 6 isin an extended position with the lug members 20 in contact with the, clutch members 23. The rotation of the drill string will be transmitted to the drill or core bit through the contact of the lug members 20 with the lug portions. 30 of the clutch members 28. The extended tool. may thus be rotated in a right hand direction. to continue the drilling operation, or the tool may be rotated in a left hand direction to back oif, if desired.

The outer drive sleeve 18 and housing 14 move upwardly within the well bore completely independent of the inner drive sleeve 36 and packing stem 24. Thus, the upper portion of the drill string may be raised sufliciently at the surface of the well for inserting additional sections of drill pipe without disturbing the bit on the bottom of the well bore. When the additional drill pipe section has been added, the drill string is lowered slowly within the well bore. As the open end 22 of the outer drive sleeve 18. moves telescopically downward over the contact between the helical surfaces 52 and 54 causes the outer sleeve 18 to rotate in a right hand direction and move the lugs 20 into the female spline groove 42. A continued downward movement of the drill string will cause the lugs 20 to travel downward in the spline 42 until the helical portion 54 of the lug 20 comes into contact with the helical shoulder 50 of the horizontal groove 46v as shown in Fig. 2, thus causing a further right hand rotation of the outer sleeve 18 to position the lug 20 at the lower end of the groove 46 adjacent the shoulder 33. The drill string may now be raised to position the 111g 20' adjacent the shoulder 48 as shown in Fig. 1-A, and the drilling operation may be continued as hereinbefore set forth.

The slip. joint 6. is so designed and constructed with the downwardly diverging helical portions to automatically position the lugs 20 within the femalesplines 4!) without a right hand rotation of the drill string. by the kelly at the surface of the well, and thereby assuring a proper positioning of the telescoping joint in an efficient and expeditious manner. This automatic coupling of the slip joint precludes a hunting operation, on the part of the operator that is usually necessary to. find the proper groove for positioning the lug therein which subsequently must be rotated and positioned in a cooperating groove. The/diverging helical portions cooperate in a manner to assist an automatic disposition of the lugs.

within the proper groove so that the drill string can be moved. vertically upward during the drilling operations, In the event the drill or core bit becomes stuck in the well bore, and it is necessary to back olfthe drill string,

the drill string is lowered as hereinbefore set forth and rotated in a left hand direction to release the outer drive body 18 for telescopic movement upward with respect to the inner drive body 36. The drill string is. then raised to move, the outer housingi14- and outer sleeve 18. upwardly over the inner sleeve 36 until the lug, members 20 are brought into engagement with the clutch and stop members 28 as hereinbefore set forth. This clutch ing engagement locks the outer drive sleeve 18 and the inner drive sleeve 36 for either left or right hand rotation, as resquired, in order to facilitate the freeing of the stuck bit.

The drilling fluid normally flows longitudinally through the central bore of the drill string and slip joint directly to the bit at the lower end of the drill string for facilitating the drilling operation. When the tool is in an operating position, or a non-extended position, the drilling fluid passes through the central bore of. the packing stem 24. and through the slip joint 6 and drill string therebelow to the drill bit. The packing members 26 preclude the fluid from flowing between the inner and outer drive bodies thereby assuring an efiicient operation of the slip joint as well as assuring that the fluid will be directed to the bit for facilitating the drilling operation. Since the inner drive sleeve 36 and the bit are not moved longitudinally within the well bore during the telescoping operation of the slip joint 6, the flow of the fluid to the bit is not disturbed when the tool is in an extended position, and therefore no packing members are required at the lower portion of the slip joint 6 for precluding any undesirable recirculation of fluid through the tool during either an extended position or an operating position of the slip joint. Furthermore, any of the fluid flowing downwardly through the extended tool and which may pass into the annular space between the inner and outer drive bodies tends to maintain the control spline members free of any accumulation of debris, and the fluid and debris fall harmlessly out the open end 22 of the outer drive body 18 into the well bore. Thus, only one set of packing members are required for an efficient operation of the slip joint 6.

From the foregoing, it will be apparent that the present invention contemplates a slip joint assembly which permits the insertion of an additional section of pipe in the drill string without removal of the drill or core bit off the bottom of the well bore. It will be apparent that this is accomplished by a telescopic type of slip joint having cooperating male and female splines which necessitate a continuous feed of the rotating kelly of the drill string to provide for variation in the desired weight for penetration of formations of variable densities which is communicated to the drill bit. The spline members are provided with complementary helical surfaces or shoulders for facilitating the engagement of the male lug members within the female grooves without additional right hand torque applied to the drill string. The cooperating helical surfaces automatically align the lugs with the grooves in a manner that eliminates a hunting action by the operator. The lugs are automatically moved into a complete disposition within the grooves without the necessity of rotating the drill string from the surface of the well bore. The helical surfaces also cooperate in the releasing of the lugs from disposition within the grooves when it is desired to telescopically extend the tool for inserting an additional section of drill pipe within the drill string. Thus, the helical surfaces greatly facilitate the entire telescopic operation of the slip joint.

Furthermore, the slip joint provides for a predetermined Weight on the bit which may be easily calculated to assure a speed of rotation of the drill complementary to the speed of penetration of the formation by the drill bit to assure that there is an eflicient feeding of the kelly relative to the spline members, and there will be a limited drilling off because the shoulder 48, by virtue of its contact with the upper end of the key 20, prevents the deeper penetration of the drill bit and drill collars unless there is a feeding off of weight at the Kelly joint. In addition, the slip joint assembly is locked during the lowering of the drill string into the Well bore to prevent accidental telescopic spreading thereof, and the lug members 20 cooperate with the clutch and stop members 28 for precluding accidental complete disengagement of the drive bodies during the telescopic operation of the slip joint.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

What is claimed is:

1. In a slip joint adapted to be interposed in a drill string including a bit secured to the lower portion of the drill string, an inner drive sleeve secured to the lower portion of the drill string above the bit, a cylindrical outer housing secured to the upper portion of the drill string and telescopically disposed over the inner sleeve, a plurality of circumferentially spaced lug members provided on the inner periphery of the housing, a helical shoulder provided on the lug members, a plurality of circumferentially spaced longitudinal grooves provided on the outer periphery of the inner sleeve, a horizontal groove on the inner sleeve providing communication between adjacent pairs of said longitudinal grooves, at least one of said longitudinal grooves of each connected pair provided with an open end portion for receiving one of the lug members, the other of said connected longitudinal grooves in communication with the open ended longitudinal groove being closed at both ends, a helical shoulder provided 011 the inner sleeve conterminous with the open end of the longitudinal groove for cooperating with the helical shoulder on the spaced lug members to direct the lugs into the open end of the longitudinal grooves upon a downward movement of the outer housing, a lowermost helical shoulder provided on the inner body and disposed in the horizontal groove for cooperating with the helical shoulder on the lug members for moving the lugs into said closed ended longitudinal grooves, said grooves cooperating with the lug member t provide alternate extended and contracted positions for the slip joint, a plurality of stop members provided on the inner sleeve and spaced above the grooves for cooperating with the lug members topreclude accidental complete disengagement of the inner sleeve and housing upon an upward movement of the housing, said stop and lug members permitting simultaneous rotation of the housing and inner sleeve in an extended position of the slip joint.

2. In a slip joint adapted to be interposed in a drill string, an inner drive sleeve threadedly secured to a lower portion of the drill string, an outer housing threadedly secured to an upper portion of the drill string, a sectional cylindrical housing threadedly secured to the outer housing and telescopically disposed over the inner drive sleeve, a packing stern provided for the inner drive sleeve, a plurality of packing ring members provided on the outer periphery of the packing stem to preclude leakage between the packing stern and outer housing during a telescopically contracted position of the slip joint, 21 plurality of circumferentially spaced lug members provided on the inner periphery of the sectional housing, a plurality of substantially J-shaped grooves provided on the outer periphery of the inner drive sleeve, said grooves having one end open to receive the lug members, a helical shoulder provided on the inner sleeve conterminous with the open end of the grooves for directing the lug members into the grooves, a lowermost helical shoulder provided on the inner body and disposed in the horizontal groove of the J-shaped groove for directing'the lugs into a full engagement with at least one of the J-shaped grooves, said J-shaped grooves and lugs cooperating to provide alternate telescopically extended and contracted positions for the slip joint, stop means provided on the packing stem for cooperating with the lug members permitting a simultaneous rotation of the inner sleeve and sectional housing in an extended position of the slip joint and preclude accidental disengagement of the housing and inner drive sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,600,744 Thomas Sept. 21, 1926 2,065,262 Barkelow Dec. 22, 1936 2,309,866 Reed Feb. 2, 1943 2,506,795 Koeln May 9, 1950 2,572,895 Waggener Oct. 30, 1951 2,851,252 Le Bus Sept. 9, 1958 2,852,231 Le Bus Sept. 16, 1958 

